In general, in medical research, it is very important to acquire local, biological information in a target sample in order to investigate cell-substrate correlations.
The observation of human tissues using a radiological approach has conferred a great benefit to human civilization thanks to its advantages, such as noninvasiveness. In the fields of biotechnology and medical science, the radiological observation of micrometer-sized tissues has highly contributed to numerous research and development activities, making significant improvements toward human welfare.
However, since currently there is no effective method for correlating micro- or nano-sized structure information with biological information, there is a need for the appropriate combination of technologies and experiences for the development of new imaging technology as the way forward for the future.
With regard to this, conventional radiation apparatuses have millimeter-level resolution but cannot observe minute (micrometer-sized) tissues due to lack of spatial resolution, and thus there is a limitation in that such tissues must be observed by utilizing massive radiation using a particle accelerator.
Such a particle accelerator has a spatial limitation attributable to the use of particle acceleration facilities, thus resulting in a difficulty with making autonomous observations.
Furthermore, conventional micro X-ray machines have limitations in terms of application to various imaging apparatuses because the emitted X-ray flux of a tube having 8 micrometer-level resolution at an electron-emission current per unit area of 0.1 mA is insufficient due to the use of a filament-based electron emission source.
Meanwhile, conventional X-ray sources are disadvantageous with its electron beams or X-rays generated in low quality due to disproportionate accelerated electron energy levels, its inability to provide the desired size or electron emission element, and the increase in size of focusing electrodes and gate electrodes due to high early electron emission diffusion.